Hi, help me with "system too lean" problem.

[anxious]

Hello, everybody,

The check light of my Toyata Corolla 2001 LE was turned on. And "System too lean" was read out through the computer. The O2 sensors were REALLY not working and replaced with new ones. Surprisingly, the check light come back at about 50 miles after the replacement. Could you guys do me favors on this problem?

thanks!

[fredk]

too much air and not enough gas, look for a vacuum leak or dirty injectors or more ideas

[anxious]

Thank you, fredk!

[fredk]

keep in touch

[94_Rolla_Guy]

another few ideas dirty fuel filter, lazy fuel pump causing less than sufficient fuel pressure

[rated_w]

I had an engine too lean code pulled from my ecu a few months back.. it was the MAF sensor..

appearantly, the MAF sensor is a common problem with the 1zzfe as well as the echos.. are you experiencing any hesisitation problems?

[anxious]

Hi, rated_w,

As you said, every time I had the check light turned off (Unplug the EFI fuse for 30~60 seconds), the car hesitated to start fast or speed up even I step very heavily on the pedal. Do you think that's MAF sensor problem?

thx.

[rated_w]

that is precisely what I had happen

I would press the gas.. the rpms would drop for a split second.. hesitate and then go... once I even pressed the gas, and it sputtered for a good 3 seconds when I was making a left turn..

can you get the rpms over 3000 rpm? if you can't it's a good indicator that your maf sensor is gone

IMO it sounds like the MAF sensor to me .. dixie toyota has sold more than 300 maf sensors to corolla owners this year alone.

dealership will charge you 250 Canadian for the sensor (not too sure about american), try to look on ebay or somewhere around there before going to dealer.

If you are looking for the MAF sensor, it's right by the airbox just before the tube that goes into the throttle body..

[anxious]

Hi, rated_w,

I wanna appreciate your great idea. After I had my AMF sensor cleaned, the problem totally disappeared. So, the sensor still works, but it was really dirty. Anyway, the garage guy cleaned it professionally.
Thank you.
My thanks are also due to fredk and 94_Rolla_Guy, your ideas helped me maintain my baby.

good luck to all you guys.

[ShawnM]

You beat me to it! First thing to try is a blast of carb cleaner on the MAF sensor wires. Small fibers from cheap air filters can also coat the sensor wires and cause the same type of lean code and hesitation.

[rated_w]

glad to see it worked out

I was unlucky when I tried to clean mine.. it didn't work.. I cleaned it with electrical parts cleaner.. tried throttle body cleaner too and even carb cleaner...... and it didn't work.. so I had to get a new one ...

enjoy driving your baby.. I know I do